Process for producing beta-(alkyl mercapto) ethyl chloride



Patented May 27, 1952 PROCESS FOR PRODUCING fi-(ALKYL' MERCAPTO) ETHYLCHLORIDE John K. Fincke, Dayton, Ohio, assignor to Monsanto ChemicalCompany, St. Louis, Mo., poration of Delaware No Drawing. ApplicationFebruary 24, 1948,

' Serial No. 10,587

This invention provides an improved process for producing ,B-(alkylmercapto) ethyl chlorides.

An object of this invention is to provide an improved process forproducing fl-(alkyl mercapto) ethyl chlorides by the reaction of thecorresponding alcohol and hydrogen chloride.

I have found that by treatin a 13-(alkyl mercapto) ethanol, wherein thealkyl group contains at least 6 carbon atoms, with hydrogen chloride, agood yield of the corresponding chloride may be obtained.

In prior processes in which alcohols or ethers are treated with hydrogenchloride in order to form the corresponding chlorides, it has been thepractice to conduct a reaction in the presence of metal halides whichabsorb the water formed in the reaction. In accordance with the presentinvention I have found that B-(alkyl mercapto) ethanols, wherein thealkyl group contains from 6 to 18 carbon atoms, may be treated with H01and the corresponding chlorides obtained in good yields and without theemployment of metal chloride catalysts as dehydrating agents.

According to the present invention the treatment of mercapto ethanols iscarried out upon the alkyl mercapto ethanol in the liquid phase and at atemperature above the melting point of the alcohol but below 100 C. TheHCl is preferably employed in the gaseous anhydrous form, althoughliquid anhydrous I-lCl may also be employed by a proper arrangement ofthe apparatus and the operating conditions. The alkyl group in thep-(alkyl mercapto) ethanol may be any aliphatic group of normal,branched or cyclic configuration.

The following examples will illustrate the practice of my invention:

Example 1 p (n Octyl mercapto) ethyl chloride.50 grams (0.262 mole) of,B-(n-octyl mercapto) ethanol was charged to a 500 cc. flask providedwith a gas inlet tube, a stirrer, a reflux condenser and a thermometer.Anhydrous HCl gas was passed into the fi-(n-octyl mercapto) ethanol atroom temperature. The reaction heat caused the temperature to rise to 84C. Shortly after the maximum temperature rise occurred, unabsorbed HClappeared in the exit tube, indicating the reaction to be nearlycompleted.

Three layers separated out upon standing. A top layer constituting alarge proportion of the reaction mass, a small dark middle layer and aclear bottom layer (probably HCl and H20) 2 Claims. (01. 260-609) wasvisible. The addition of HCl was again commenced and continued for.another hour at a temperature of C. to C., maintained by theapplication of heat. At the end of this time the small, dark, middlelayer product had almost disappeared. The entire product was dissolvedin ethyl ether, washed with water, then with dilute potassium carbonate,dried and distilled. Yield: 89:0%,n =1.4741. Boiling range 11'7-119.5C./4 mm. pressure. Analysis: per cent S found=l5.87%; theory=15.3.

Example 2 fl-(n-Decyl mercapto) ethyl chZorz'de.--'236 grams of crudefi-(n-decyl mercapto) ethanol prepared by. the addition of p-mercaptoethanol to n-decene was charged to a 3-necked, 500 cc..

flask fitted with a gas inlet tube, mechanical stirrer, thermometer andreflux condenser. A flow of anhydrous HCl gas was started. whereupon thetemperature of the reacting mass rose to 60 C. within a few minutes. Theflask'was cooled by means of a water bath sufliciently'so as to keep thetemperature of the reaction below C. After approximately 1 hours thetemperature had dropped to 33 0., and the reaction was consideredcomplete. The flask contents were transferred to a separatory funnel andthe HC1H2O layer separated. The material was then distilled and theproduct distilling over a boiling range of 1 18-121 C./1 mm. mercurypressure was recovered. Yield: 81% of theory. Color, Water white. vl=l.4750.

Example 3 ,c-(n-Dodec'yl mercapto) ethyl chloride-150 grams B-(n-dodecylmercapto) ethanol was charged to a 500 cc. flask provided with athermometer, a water cooled condenser, propellerstirrer and an HCl inlettube. A flow of an hydrous I-ICl gas was led into the material, thetemperature rising rapidly to C., at which point the flask was cooled toprevent further temperature rise. After approximately 45 minutes thetemperature had fallen to 50 C. to 55 C. At this point'HCl gas could bedetected at the exit of the condenser. The addition of HCl gas wascontinued for one additional hour, the temperature being maintained at40 C. to 50 C. The flask contents were then removed, dissolved in etherand the water layer separated from the resulting emulsion as completelyas possible. The remaining ether and water was removed by evaporation.The dry residue was distilled over a boiling range of 152-153 C./1.0-

"1.5 The product weighed 96 grams.

' was placed 'in 'the reaction flask, describedin Example? above; andanhydrous HCl gas passed 1 in. The temperature was kept below 60 C. bymeans of a-water bath. At the end of 40.minutes the reaction appeared'to.be complete, thermatle rial was transferred to a separatory-funnel andthe lower layer drawn off. The product was dried under a vacuum anddistilled.- -Theproduct boiling-over a rangeof 73-78 C./1 mm. was 7collected. n =1.4869. Yie1d-V ,*68%.' V 7 V K Emample i r I came)ethanol having: ahoiling .rangepi hi0, H29": uYIAJmzm iwasi charged; to;thacreactiom fiasltempleyed? injExample 2Ial'oove; Anhydrous. HG!-wasbadde d; whereunonthe: temperaturemose r rapidlyntmflwv Cooling water.wastaph i dr the. fiaskzztoz keen-"the; temperature cbelow'w '70?After-approxhnatelyone hour; the; tempera! ture had dreppeditonyw-f 6.and-the reaction was ramsis finrmadecyl memento eth m l w s;

char ed- :tet e: as Videscribedin- Exam le :2 ab vezandast eam e anh dmsHGL-ga pas 1131 11 43" the addition of the gas -no 1' sharp- 1temperaturesrise: noted; hoszvever, water-was el afl iu i i na a n-= a w'warme FY30? C tel-00C. until thefcrystallib oi thecontents; dropped:to: about 30- 0., which was approximately three hours; Water waswithdrawn under a vacuum. The material remaining in the flask hadacrystallizing point of C. The flask was again warmed .to C. for onehour and HCl passed into it. No

ffurtherrevolnti'on of water. was observed. The

product was again dried at 6. under 1 mm.

7 pressure.

x ie1d= 104=.6 grams. Approximately ,of "theory was obtained.

The crystallizing point was 35 C.

-- What-lifelaim is: V

1. The process for producing a fi-(alkyl mercapto) -.'ethyl chloridewhich consists in treating a palky1* -mercapt0) ethanol wherein thealkyl group hasfrom 6 to 18 carbon atoms, with anhydrous hydrogenchloride at a temperature 7 ault? the melting point of the said.p-(alkyl I V r V V V mercapto) ethanol, but below 100 C. 1 fl-(Tertiarytetradecyl mercapto) ethyl" chloride.200 grams of .fi-(tertiarytetradecyl mer-' 2} The "process for producing p-(octyl mercapto) ethylchloride which consists in treating fi-ioctyl mercapto) ethanol withanhydrous hydrogen chloride at=a. .temperature above the melt-'- ingpbintiof thets'ai'ui fl-toctyl mercapto)iethanol, but'below 100 C. i

r JQEN'KLFI-NCKEQ ransm ssions 0mm I'he following-references iareofrecordin the v fiieg ofjthis'patent-:

' UNITED STATESPAEENTS Bennett's J C. S; (London); vol. lzl page2l-45('1922),.V

Elswier. Bub. 10.0., .Nordeman Pubs-Co

1. THE PROCESS FOR PRODUCING A B-(ALKYL MERCAPTO) ETHYL CHLORIDE WHICHCONSISTS IN TREATING A B-(ALKYL MERCAPTO) ETHANOL WHEREIN THE ALKYLGROUP HAS FROM 6 TO 18 CARBON ATOMS, WITH ANHYDROUS HYDROGEN CHLORIDE ATA TEMPERATURE ABOVE THE MELTING POINT OF THE SAID B-(ALKYL MERCAPTO)ETHANOL, BUT BELOW 100* C.